We recently learned of this amazing 3D-printed Mignon index typewriter, published on Thingiverse.
Its creator, Keenan Finucan, now shares some fascinating background.
This interview was conducted by Viennese typospherian Rodja Pavlik and will be published in German translation on his blog, Die Schreibmaschinisten. It is reproduced here with permission.
Rodja Pavlik: So... can you tell me something about yourself? Who are you, where do you live? How old are you? What do you do for a living? Do you have a homepage I should link to?
Keenan Finucan: I live in the Madison, Wisconsin area, and have lived in Wisconsin for most of my life. I am 37, not currently working. I was in need of a break, and after being quite careful with my money for years, I left my job in late 2024, which gave me the bandwidth to complete a few things, including my typewriter project. I've been interested in 3D printing for a while, getting my first machine, a Solidoodle 2, around 2012.
My previous job for over 8 years was actually in industrial 3D printing, primarily in the role of a technician. So, I'm familiar with many 3D Printing technologies, including ones that are not readily available to hobbyists such as SLS (Selective Laser Sintering) and SLA (Stereolithography). My relevant education includes a technical degree in Prototype and Design, which included CAD, fabrication, machining & prototyping.
I have a portfolio of work hosted at https://www.coroflot.com/keenanfinucan.
Are you interested in typewriters in general — or just the Mignon? What drew you to the Mignon?
I am not a passionate collector, but I certainly appreciate the engineering of typewriters: their mechanical complexity, their tactile, analog nature. I have a small collection including -naturally- the Mignon Model 4, an original Selectric, a 50s Remington, a 60s Silver Reed from a rummage sale that I've had since childhood. Mercifully I never took it apart or otherwise destroyed it! Honestly I only rarely make use of them, but even still I like to think that I am keeping them safe for the future. Not so much for monetary gain, rather, I like to think that people's appreciation for devices from this era will only grow in the future. Despite manufacturing becoming more and more advanced over time, making true replicas of these machines will remain impractical for the foreseeable future. They were made this exact way once, and never again.
I think I first saw the Mignon demonstrated in an overview of old typewriters in an episode of "The Secret Life of Machines - The Word Processor" on Youtube. To those unfamiliar, it was a BBC series of the late 80s till early 90s, presented by Tim Hunkin, and broke down the engineering and history of items in our daily lives. A delightful series full of practical explanations and demonstrations.
I think I first saw the Mignon demonstrated in an overview of old typewriters in an episode of "The Secret Life of Machines - The Word Processor" on Youtube. To those unfamiliar, it was a BBC series of the late 80s till early 90s, presented by Tim Hunkin, and broke down the engineering and history of items in our daily lives. A delightful series full of practical explanations and demonstrations.
I had been thinking about the possibility of making a 3D printable typewriter for some time, and knew that a traditional keyed typewriter would be a bit too much of an undertaking. I was familiar with some of the stamped tin toy typewriters that have a unified type element, but these were extremely slow, had few features, and poor quality. Remembering that segment of the show I had seen a year or two prior, I found the exact time where that machine appeared, and I easily identified it from the huge MIGNON lettering on the paper feed panel. After a bit of online research, I thought the design was simple enough that I might be able to make it 3D printable. I bought a somewhat affordable Model 4 on eBay, not easy to do when they are rare in the USA, and the hassle of international shipping means European sellers can command high prices even before the shipping costs themself are considered.
The mechanism of the Mignon is ingenious, and rather satisfying to use. AEG may have economized on the number of parts, but the actual quality of the machine is very high. I have few points of comparison, but I can see why it is regarded as among the best Index machines.
Did you have a construction plan of a Mignon? Or did you just imagine the function and put it into work? Like reverse engineering?
I didn't find any drawings for the Model 4. I used direct measurements taken off of my Mignon as a starting point for modeling (Autodesk Fusion) and then did a lot of iteration and testing of printed parts.
Prototype parts
Prototype baseplates
It was really a combination of reverse engineering, along with adapting the parts for 3D printing. This meant creating geometric relationships between my parts that matched the original machine, while redesigning parts to be thicker than the originals to account for the low rigidity of plastic. I also tried to design every part to avoid support structure when printing. Furthermore, I wanted to make the project as accessible as reasonably possible to other hobbyists. Having a very long list of hardware required would only limit the number of people who actually complete the project, so I tried to make as many parts 3D printable as possible and avoid screws and nuts. Because of all these considerations no single part is interchangeable with the original Model 4. Early on I had the idea that I would even 3D print plastic springs, but this was a bit of a fantasy as the plastic is guaranteed to deform over time. I settled on an assortment of metal springs that can be sourced from commonly available kits.
In case you are wondering, the font is Erika Type. It was the closest I could find to my original type cylinder.
How long did you take to make a Mignon? From the first plan to the final functioning typewriter?
I had started an early version of the project around 2021 but lost momentum and set it aside after a few months. After the purchase of a faster, larger 3D printer (BambuLab X1 Carbon), and leaving my job, I decided to try again in late 2024 and started the whole design again. The entire process was a bit over a year of intermittent work. I had something approaching "functioning" after maybe only 3 months, but from my experience going from 0 - 95% was easier than the final 5%. Creating assembly instructions was no small part of the task: condensing down steps, creating renderings, and trying to imagine how the average person is going to read them and where they will encounter problems.
And how long does a session take to make one typewriter?
This depends hugely on what your 3D printing capacity is. If you have one fast modern printer, perhaps a minimum printing time of ~2 days for all parts. If you had a slower machine, and maybe some printing jobs that end when you're sleeping or out of the house, it could be 4 days. The actual assembly is far less time consuming, perhaps 3 hours? To be honest this process has been so iterative that I have never done all printing and assembly back to back.
Was this just for fun - or do you have some plans for the future with producing Mignons?
For something like this, pain and fun are very intertwined! What drove me to complete this was to have it as an impressive portfolio piece, no one has replicated a real typewriter before. I know I could have charged money for the files, but I've come to realize that only a small fraction of designers are making significant money from their designs, and it's more valuable to me to see more people complete the project. I don't intend to start manufacturing these: the long printing time, difficulty of shipping, and a lack of real world stress testing all give me pause. Although I am very proud of this project, please consider it a first of its kind 3D printable novelty. The best Mignon is an original Mignon. I also like to think that this is a demonstration of what is possible, and maybe someone can build on my work to make something even more complicated or with higher quality imprints.
To any hobbyists looking to design their own 3D printable typewriter, search for the Gundka Typewriter (and the other brands it was sold under). Its design definitely seems like a "cousin" of the Mignon, and it has a much lower parts count than a traditional typewriter.
Did you have reactions to it from the typewriter community?
I did share this with some people and a handful were quite intrigued. It remains to be seen what the overlap between typewriter enthusiasts who have a 3D printer, and who actually will complete this is.
Do you have other photos? Even a video on Youtube?
I may or may not upload a full Youtube video. I'm not much of a videographer, and despite my real name already being out there, perhaps I don't want my public profile to rise too high. I did finally create a WebP moving image on Thingiverse, as I want to seize the moment while it is highlighted as a featured design.
Detail of bottom and "margin counter": Instead of a bell, I designed this lever to indicate the last few spaces until the margin stop. Is it more practical than a bell? Maybe not, but it is unusual.
What do you plan next?
Sometime in the next few months I plan to reenter the workforce, ideally in prototyping and industrial design. I may have another design project in me before that, but I am not planning something as ambitious as this! I will also be keeping an eye out for the community's reaction to the typewriter, and if needed provide help or redesign parts.
PS from Richard: Keenan added the following reflections in an email exchange with me:
From my point of view, even with 3D printing, making true replicas of machines will remain difficult and prohibitively expensive for the foreseeable future. Metal 3D printing is not cheap, and all parts would need to be modeled, printed as discrete parts, hand finished, and then assembled. And that's before considering parts like springs with material properties that can't be 3D printed. Despite being "high tech," and continually improving, 3D printing can be quite uneconomical for mass production, but instead excels at creating custom parts without the need to engineer and build bespoke tooling. I think creating a modern typewriter at a reasonable price is more a question of demand than the capabilities of 3D printing technology. If you were assured that 50,000 people would buy one, you could justify the complicated and expensive tooling (the same as how the 20th century machines were produced) to quickly and cheaply manufacture every part, and get the per unit cost down lower than an all 3D printed design. Supply and demand as it stands today likely means that buying an old machine will be the most economical choice for some time. I think the most practical use of 3D printing in regards to typewriters is to create custom parts to repair the machines that already exist.
Although I am very proud of my design, I consider it to be a first of its kind novelty aimed at 3D printing hobbyists, yet I like to think it may inspire others to go further and create even more complicated designs. A design based on plastic will unfortunately struggle to reach the quality of an all metal original.
Modern CAD design, 3D printing, CNC machining, and the advent of online manufacturing services are a powerful combination. One person, from their home, maybe could recreate a traditional typewriter in metal if they had the passion and engineering skills, but at a prototype scale of manufacturing the economics are the true limiting factor.
PPS: Now go to YouTube and see how Koenkun Bricks managed to built a functional Lego typewriter! (Or should it be called a Linotype?)
